Parallel voltage regulator

ABSTRACT

A parallel voltage regulator having an improved factor of stabilization since a reference voltage from a Zener diode is used, this Zener diode being supplied, via a resistor, with a stabilized auxiliary voltage. The stabilized auxiliary voltage is obtained as the sum of an output voltage and of a voltage drop in a semi-conducting diode polarized in a specific direction.

Martynow et al.

PARALLEL VOLTAGE REGULATOR Inventors: Wieslaw Martynow, ul. Grojecka 102/ 149; Stanislaw Wilkowski, ul. Grojecka 102/33; Wojciech Michalowski, ul. Chlodna 41/74, all of Warsaw, Poland Filed: Sept. 26, 1973 Appl. No.: 401,108

Foreign Application Priority Data [4 May6, 1975 Primary Examiner-A. D. Pellinen [5 7] ABSTRACT A parallel voltage regulator having an improved factor of stabilization since a reference voltage from a Zener Oct. 2, 1972 Poland 158039 diode is used this Zener diode being Supplied, Via a resistor, with a stabilized auxiliary voltage. The stabi- U.S. Cl. 323/8; 323/22 Z li auxiliary Voltage is obtained as the Sum of an Int. Cl. G05f 1/60 output voltage and of a voltage drop in a Semi held of Search 323,1 19, 22 conducting diode polarized in a specific direction.

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PARALLEL VOLTAGE REGULATOR FIELD OF INVENTION The present invention relates to parallel voltage regulators with improved factors of stabilization, and more particularly to regulators designed primarily for use in battery-type measuring instruments.

PRIOR ART One voltage regulator of known type comprises a differential amplifier, a transistor of the n-p-n type, a Zener diode, and resistors.

These elements of the voltage regulator are connected in the following way:

A first terminal of a first resistor is connected with a first input terminal while a second terminal of a second resistor is connected with a first terminal of a third resister, with the collector of the transistor which performs a regulating function, and with a first output terminal. The second terminal of the second resistor is connected with the cathode of the Zener diode and with a first input of the differential amplifier. A second terminal of the third resistor is connected with a first terminal of a fourth resistor and with a second input of the differential amplifier. The output of the differential amplifier is connected with the base of the regulating transistor. The second output terminal, the anode of the Zener diode, a second terminal of the fourth resistor, and the emitter of the regulating transistor are connected with a point whereat appears the reference potential of the system.

This system is designed for regulating output voltage irrespective of variations in load current and in supply voltage. Despite the fact that performance of the above described system is generally satisfactory, its use in battery-type measuring instruments is objectionable because of a high current input to the divider formed by the third and the fourth resistors connected together. Also, the output voltage obtained from this system is higher than the voltage of the Zener diode by the value of voltage drop in the second resistor, this voltage drop being usually no less than 1 V.

Therefore, if Zener diodes for current production and of a voltage of from 3 V upwards are used, the voltages obtained in the above-described system may be more than 4 V.

SUMMARY OF INVENTION An object of the present invention is to eliminate the shortcomings and imperfections of the above-described known type of voltage-regulator system.

This object is attained by a new and simplified system in which the first terminal of the first resistor is connected with the first input terminal, while the second terminal of this resistor is connected with the first terminal of the second resistor and with the anode of the semi-conductor diode. The cathode of the semiconducting diode is connected with the first input of the differential amplifier, with the collector of the regulating n-p-n type transistor, and with the first output terminal. The second terminal of the second resistor'is connected with the cathode of the Zener diode and with the second input of the differential amplifier. The input of the differential amplifier is connected with the base of regulating transistor. The second output terminal, the anode of the Zener diode, and the emitter of the regulating transistor are connected with a point whereat appears the reference potential of the system. The thusly constituted voltage regulator has a very good energy efficiency and it permits obtaining low output voltages of, for example, from 3 V up,

The above-mentioned qualities of the novel voltage regulator are, furthermore, achieved by including in the system a semi-conducting diode the voltage drop across which increases the stabilized output voltage supplying the Zener diode through the second resistor. In this way, the current flowing through the Zener diode has a constant value governed by the voltage drop of the semi-conducting diode and by the voltage drop across the second resistor.

BRIEF DESCRIPTION OF DRAWING An embodiment of the invention will next be described, by way of example, with reference to the accompanying drawing in which the sole FIGURE is a schematic diagram of a regulator provided in accor dance with the invention.

DETAILED DESCRIPTION A first terminal of a first resistor R is connected with a first input terminal 1 of the regulator. The second terminal of the said resistor R is connected via a junction J with a first terminal of a second resistor R and with the anode A of a semi-conducting diode D The second terminal of the second resistor R is connected via junction J with cathode K of a Zener diode D and with the first input of a differential amplifier A. The cathode of the semi-conducting diode D is connected via junction J 3 with the second input of differential amplifier A, and via junction I, with the collector C of an n-p-n type regulating transistor T and with a first output terminal 3. The output of the differential amplifier A is connected with the base B of the regulating transistor T. A second input terminal 2, the anode A of Zener diode D an emitter E of the regulating transistor T, and a second output terminal 4 are connected with a point whereat appears the reference potential of the system.

The supply voltage U is applied to input terminals 1 and 2. The reference voltage U for the differential amplifier A (said amplifier being the amplifier of error voltage) is supplied by the Zener diode D Voltage U is applied to the first input of the said amplifier A. The stabilized output voltage U is taken from output terminals 3 and 4. A power absorbing resistor R may be connected to the said output terminals.

In accordance with the operating principles of highamplification-rate differential amplifier A, the output voltage U is the same as the voltage in Zener diode D The voltage drop in resistor R plus the voltage drop in Zener diode D is equal to the output voltage U plus the voltage drop in the semi-conducting diode D provides that an already stabilized voltage is applied to the Zener diode D through the resistor R thus improving the stabilization of the system.

An increase in auxiliary voltage by means of semiconducting diode D causes, first of all, that the drop of voltage in resistor R is increased. The current of the Zener diode D is proportional to the voltage drop in the semi-conducting diode D,, because this drop is equal to the voltage drop in resistor R In this way, the relative changes in the supply voltage U are obtained, since the voltage drop in the semi-conducting diode D depends only slightly on the current of diode D,. Thus,

thestabilization of the current of the Zener diode D is obtained, this being the main objective.

What is claimed is:

1'. A parallel voltage regulator having an improved factor of stabilization, said regulatorbeing adapted for use in battery-type measuring instruments, said regulator comprising first and second output terminals, a differential amplifier including first and second inputs and an output, an n-p-n type regulating transistor, a Zener diode including a cathode and anode, a semiconducting diode including a cathode and anode, and resistors each including first and second terminals, the

. first terminal of the first resistor being connected with 7 said first input terminal, the second terminal of the said first resistor being connected with the first terminal of said secondresistor, the second terminal of the said second resistor being connected with the cathode-of said Zener diode and with the first input of said differ ential amplifier, a regulating transistor including a base,

collector and emitter, the second input of the said differential amplifier being connected with the collector between the first resistor and the second resistor,

the cathode of the said semi-conducting diode being connected with the second input of said differential amplifier whereby the Zener diode is supplied, through the second resistor with an output voltage increased by the value of voltage drop across the semi-conducting diode, the sum of the current of a load and of the regulating diode flowing through the said semi-conducting diode.

2. A regulator as claimed in claim 1 comprising a load impedor coupled between said output terminals. 

1. A parallel voltage regulator having an improved factor of stabilization, said regulator being adapted for use in batterytype measuring instruments, said regulator comprising first and second output terminals, a differential amplifier including first and second inputs and an output, an n-p-n type regulating transistor, a Zener diode including a cathode and anode, a semiconducting diode including a cathode and anode, and resistors each including first and second terminals, the first terminal of the first resistor being connected with said first input terminal, the second terminal of the said first resistor being connected with the first terminal of said second resistor, the second terminal of the said second resistor being connected with the cathode of said Zener diode and with the first input of said differential amplifier, a regulating transistor including a base, collector and emitter, the second input of the said differential amplifier being connected with the collector of said regulating transistor and with said first output terminal, the output of said differential amplifier being connected with the base of the said regulating transistor, and a point at which appears a reference potential of the system, the second input terminal, the anode of Zener diode, the emitter of the said regulating transistor, and said second output terminal being connected with the point of the reference potential of the system, the anode of the semi-conducting diode being connected with the junction between the first resistor and the second resistor, the cathode of the said semi-conducting diode being connected with the second input of said differential amplifier whereby the Zener diode is supplied, through the second resistor with an output voltage increased by the value of voltage drop across the semi-conducting diode, the sum of the current of a load and of the regulating diode flowing through the said semi-conducting diode.
 2. A regulator as claimed in claim 1 comprising a load impedor coupled between said output terminals. 